SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e56989d7e9e2ef5bef039e42a0d9a9d22553b13cec8fa85e95f1cd6fb44a856f' 
  AND token = 'wgCJQoI9XhMHNbUbVQZKvZlFWtdQ+bKqDVHOwhLsJRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}